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• \begin{thebibliography}{}\bibitem {1} N.N. Tarkhanov, {\it On the integral representation of solutions of systems offirst-order linear differential equations in partial derivatives andsome of its applications,} Some questions of multidimensionalcomplex analysis. Institute of Physics, USSR Academy of Sciences,Krasnoyarsk, (1980) 147--160.\bibitem {2} N.N. Tarkhanov, {\it On the Carleman matrix for ellipticsystems,} Dokl. Akad. Nauk SSSR. 284 (1985), no.~2., 294--297.\bibitem {3} N.N. Tarkhanov, {\it The Cauchy problem for solutions of ellipticequations,} Akad. Verl., Berlin, V. 7. 1995 (in English).\bibitem {4} T. Carleman, {\it Les fonctions quasi analytiques,} Gautier-Villars et Cie., Paris, 1926.\bibitem {5} M.M. Lavrent'ev, {\it On the Cauchy problem for second-order linear elliptic equations,} Dokl. Akad. Nauk SSSR. 112 (1957), no.~2., 195--197.\bibitem {6} M.M.~Lavrent'ev, {\it On some ill-posed problems ofmathematical physics,} Nauka, Novosibirsk, 1962 (in Russian).\bibitem {7} Sh. Yarmukhamedov, {\it On the Cauchy problem for the Laplaceequation,} Dokl. Akad. Nauk SSSR. 235 (1977), no.~2., 281--283.\bibitem {8} Sh. Yarmukhamedov, {\it On the extension of the solution of the Helmholtzequation,} Dokl. Ross. Akad. Nauk. 357 (1997), no.~3., 320--323.\bibitem {9} Sh. Yarmukhamedov, {\it The Carleman function and the Cauchy problem for the Laplaceequation,} Sibirsk. Math. Journal. 45 (2004), no.~3., 702--719.\bibitem {10} J. Adamar, {\it The Cauchy problem for linear partial differential equations of hyperbolictype,} Nauka, Moscow, 1978 (in Russian).\bibitem{11} L.A. Aizenberg, {\it Carleman's formulas in complex analysis,} Nauka, Novosibirsk, 1990 (in Russian).\bibitem{12} G.M. Goluzin, V.M. Krylov, {\it The generalized Carleman formula and its application to the analytic continuation of functions,} Math. Sbornik. 40 (1993), no.~2., 144--149.\bibitem{13} A.N. Tikhonov, {\it On the solution of ill-posed problems and the regularizationmethod,} Dokl. Akad. Nauk SSSR. 151 (1963), no.~3., 501--504.\bibitem{14} A. Bers, F. John, M. Shekhter {\it Partial DifferentialEquations,} Mir, Moscow, 1966 (in Russian).\bibitem{15} M.A. Aleksidze, {\it Fundamental functions in approximate solutions of boundary valueproblems,} Nauka, Moscow, 1991 (in Russian).\bibitem{16} E.V. Arbuzov, A.L. Bukhgeim, {\it The Carleman formula for the Helmholtzequation,} Sib. Math. Journal. 47 (1979), no.~3., 518--526.\bibitem{17} O.I. Makhmudov {\it On the Cauchy problem for elliptic systems in the space${\mathbb R}^{m}$,} Mat. Zametki. 75 (2004), no.~3., 849--860.\bibitem{18} I.E. Niyozov, O.I. Makhmudov {\it TheCauchy problem of the moment elasticity theory in ${\mathbbR}^{m}$,} Izv. Vuz. Mat. 58 (2014), no.~2., 24--30.\bibitem{19} D.A. Juraev, {\it The construction of the fundamental solution of the Helmholtzequation,} Reports of the Academy of Sciences of the Republic ofUzbekistan. (2012), no.~2., 14--17.\bibitem{20} D.A. Juraev, {\it The Cauchy problem for matrix factorizations of the Helmholtz equation in an unbounded domain,} Sib. Electron. Mat. Izv. 14 (2017),752--764. \\ doi:10.17377/semi.2017.14.064, Zbl 1375.35153.\bibitem{21} D.A. Zhuraev, {\it Cauchy problemfor matrix factorizations of the Helmholtz equation,} UkrainianMathematical Journal. 69 (2018), no.~10., 1583-1592. (UkrainianOriginal Vol. 69, No. 10, October, 2017). \\doi:10.1007/s11253-018-1456-5.\bibitem{22} D.A. Juraev, {\it On the Cauchy problem for matrix factorizations of the Helmholtzequation in a bounded domain,} Sib. Electron. Mat. Izv. 15 (2018),11--20. \\ doi:10.17377/semi.2018.15.002, Zbl 1387.35176.\end{thebibliography}